Chair construction



Nov. 15, 1966 J.J. GALLA ET AL 3,285,639

CHAIR CONSTRUCTION Original Filed July 2, 1963 INVENTORS 5 I JOSfPH J.6am

I P/l/Z m J MAL/4M5 BY fim mlwum ATTORNEY United States Patent f This isa continuation application of application Serial No. 292,268, filed July2, 1963, now abandoned and relates to a pedestal-type chair and itsconstruction, and

more particularly, to the assembly in such type of chair of the chairpost and chair iron.

A typical pedestal-type chair, such as the stenographic orexecutive-type office chair, commonly includes a chair post connected atits lower end to a chair pedestal and at its upper end to a chair iron,which in turn supports the chair back and the chair seat. Frequently,these components are fabricated by a different manufacturer than theultimate chair manufacturer or seller, so that they must be shipped toand be assembled by the latter to form the completed chair. The chairpost and chair iron are particularly troublesome, since they must beconnected together rigidly and with sufiicient holding capacity tosupport the full load of the chair.

One commonly followed practice in the chair business is that themanufacturer of the chair post and chair iron permanently secures themtogether such as by staking, press-fitting and pinning, or even welding;and ships them as an assembly to the chair manufacturer or seller. Thistype chair post-chair iron assembly generally is economical,structurally sound, and is ready for use in the chair. The assembly has.its disadvantages, however, since being considerably bulkier than thechair post and chair iron separately, it requires larger storing andshipping space; and being permanently connected, it cannot beinterchanged with various other chair posts or chair irons to givedifferent chair post-chair iron combinations.

An alternative practice is to ship the separated chair post and chairiron to the chair manufacturer or seller, who in turn, secures themtogether. The components being separated until used permit compactshipping and storing. However, since generally special equipment andlabors are required to assemble the components properly, most chairmanufacturers or sellers prefer the first-mentioned practice, even withits disadvantages.

Several designs provide a detachable-type connection 1 between the chairpost and chair iron, such as with a threaded connection. However, suchdesign-s have not been accepted commercially due primarily to theirhigher cost, complicated or lengthy assembly procedures, and,

lack of rigidity.

Accordingly, an object of this invention is to provide a chair post andchair iron combination which can be secured together easily and-manuallywithout elaborate tools or time consuming labors by the chairmanufacturer, seller, or ultimate user.

Another object of this invention is to provide a chair post and chairiron combination which can be assembled only according to the intendeddesign to minimize wear of or strain on the components, and whichthereafter prevent relative rotation of the components.

Another object of this invention is to provide an improved means for andmethod of forming or fabricating at least part of the structure toeffect the previous object by and upon part of the fabrication of thechair iron itself.

In order that these as well as other objects can be more fullyappreciated, reference is herein made to the following specificationincluding as a part thereof the accompanying drawings, wherein:

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FIG. 1 is a side elevati-onal view of a typical executive pedestal-typechair showing the preferred embodiment of the subject invention;

FIG. 2 is an enlarged sectional view of the subject invention as seengenerally from line 22 of FIG. 1;

FIG. 3 is an enlarged elevational view, partially in longitudinal centersection, of the connection shown in FIG. 2;

FIG. 4 is a top plan view of the connection shown in FIG. 3; and V FIG.5 is a side elevational view, partially in longitud-inal centersection,of a typical arrangement of the components and appropriate fabricatingtool members before the actual fabrication thereof.

FIG. 1 shows a typical pedestahty'pe posture chair 10 of the executivetype. The chair 10 includes a chair pedestal 12 supported on floorsurface 13 and in turn supporting vertically a chair post 14 connectedat its upper end to chair iron 16. The chair iron 16 supports the chairseat 18 and a chair back 20.

Conventionally, the chair iron 16 includes a pair of spaced side members22 (only one of which is shown in FIG. 2) adapted to be connected to theunderside of the chair seat 18. A cross member 24 extends across theunderside of the chair seat 18 and is connected to the opposite sidemembers 22. Resilient spring means, such as torsion bar 26, is connectedto the side members 22 and the cross member 24 in an appropriate mannerto produce the desired resiliency of the chair back or chair seatrelative to the chair post.

The chair post 14 is connected, as at 28 to the chair iron 16. The chairpost 14, threaded as at 30 and having an axially extending keyway 32, isconnected in an appropriate manner to the chair pedestal 12 to permitheight adjustment of the chair seat 18. A construction of the threadedconnection between the chair post and the chair pedestal can be found inPatent No. 2,999,665, issued September 12, 1961, to S. A. Erickson etal. entitled Locking Arrangement for Swivel Chair Structure.

The chair 10 shown is an executive-type chair wherein the chair back 20is fixed relative to the chair seat 18. Details of construction of thechair iron 16 shown can be found in Patent No. 2,971,569, issuedFebruary 14, 1961, to H. W. Parrott et a1. entitled Tiltable OfficeChair." Chair irons, however, can also support the chair back tiltablyrelative to the chair seat as is shown in Patent No. 2,374,350, issuedApril 24, 1945, to W. F. Herold entitled Posture Chair. Accordingly, itshould be understood that the particular improvement to be disclosedherein has application to any type chair post-chair iron combination.

FIGS, 2, 3 and 4 show the connection 28 including the cooperation of itsvarious components. The cross member 24 of the chair iron 16 has anopening 34 that receives a post support member 36. The post supportmember 36 has an intermediate shoulder 37 which bears against the lowerside of cross-member 24 to support the load of the chair. A washerelement 38 is between the cross member 24and a flattened or flaredovenp-ortion 39 on the post support member 36. The post support member36 is thus confined rigidly to the cross-member 24.

The post support member 36 is annular having a conical through-bore 4ttapered uniformly along its length to its largest cross-dimensionadjacent the chair pedestal 12. A raised key portion 42 extends axiallyof the through-bore 40. The chair post 14 is tapered at its upper end 44to an identical conical taper angle as the through-bore 40 and isadapted to fit complementally therein. Thus, the tapered end 44 of thepost 14 is larger adjacent the chair pedestal 12 than adjacent the chairseat 18.

The conical tapers 40- and 44 are tapered at a small taper anglerelative to their longitudinal center axes and engage one another oncomplementary axially extending surfaces. The tapers are thusself-locking or self-holding with one another. The basic requirement ofa self-locking taper is that the taper causes a greater frictional forcecomponent in the direction parallel to the engaging surfaces than theforce component tending to separate them. Conventionally, a self-lockingtaper has a taper angle varying from approximately /2" to A" per foot.See for example, the Morse, the Brown and Sharp, the Jarno, and theAmerican Standard Machine tapers.

The chair post and the chair iron are secured together solely by meansof the frictional forces developed between the complementary engagingsurfaces on the self-locking tapers 4t) and 44. The key portion 42 onthe post support member 36 cooperates with keyway 32 on the chair post14 to prevent rotation of the chair iron on the chair post. Also, sincethis cooperation occurs in only one rotatable position of the chair postand chair iron, by properly locating the key portion 42 relative to thechair iron, strains can be minimized. For example, when key 42 is inalignment with the axis of tilt of the chair seat, as shown, any diggingof the pointed edges of the keyway 32 into the bearing (not shown) inthe pedestal 12 upon a user swivelling in the chair is minimized. Theintegral key portion 42 readily locates this proper position even forin-the-field assembly.

It should be noted that self-locking tapers can be separated from oneanother without too much difficulty by an impact-type blow tending todislodge them. Thus, the top portion of the chair post, as at 47,projects slightly beyond the chair iron when assembled thereto so that ahammer (not shown) can be directed against it to separate the chair postand chair iron.

Also of particular significance in the subject invention is the mannerin which they key portion 42 is formed in the bore 40 of the postsupport member 36. It can be noted in FIG. that before the post supportmember 36 is secured to the chair iron it has extending from theshoulder 37 a tubular shank 52 of exterior size comparable to opening 34of cross-member 24. The exterior of the shank 52 is knurled at 54adjacent the shoulder 37. The shank is adapted to be press-fit into theopening 34 from the pedestal side of the cross-member 24 until theshoulder 37 abuts the cross-member 24. Washer 38 having an intermediateopening 55 also fits over the shank 52 and abuts the cross-member 24 onthe side thereof remote from the shoulder 37. It is contemplated thatthe flare 39 is formed by staking it over the frame member and washer.For this purpose it is desirable that the washer 38 be of a hardermaterial to withstand the staking operation without deforming.

FIG. 5 also shows a preferred tool arrangement for staking the postsupport members 36 to the chair iron 16 and for forming the key portion42. The washer 38 is placed in a recess 58 on a frame or tool table 60,and the cross-member 24 is placed over the washer 38 onto the tool table60. The shank end 52 of the post support member 36 is inserted into theopenings 34 and 55 and press-fit by means of tool 62 into thecross-member 24 until the shoulder 37 abuts the cross-member. In thisinserted position, the shank 52 projects past the washer 38 into a bore64 within the frame or tool table 60 which houses a second tool member66. The advance relative to the first tool member 62 of the second toolmember 66 against the projected end of shank 52 causes the end to bestaked over the washer 38 as at flare 39 (FIG. 3). The second toolmember 66 has an inner bore 68 which partially encloses the projectedend 69 of the shank 52 to cause the staking or flare 39 to occur morereadily.

The first tool 62 is tapered at 70 to an identical taper angle as bore40 of the post support member 36 and the taper 44 on the chair post 14.The exterior surface of the tapered tool 62 has therein an axiallyextendedkeyway 72 which is of general size and dimension as the keyway32 of the chair post 14. Upon staking of the post support member 36 tothe chair iron 16 by and upon the advance of the tool members 62 and 66toward one another, the unsupported portion of the post support member36 over the keyway 72 is deformed into the keyway. This causes thepreviously-mentioned axially extended outof-round key portion 42 on thepost support member 36. It is to be understood that the tool members 62and 66 are of sufliciently hardened material to avoid flowing during thestaking operation. After the staking operation the tool members 62 and66 are withdrawn, and the components removed from the tool table 60'.

Thus, the key portion 42 is formed simultaneously with the staking ofthe post support member 36 to the chair iron, and is formed bydistorting the normal symmetrical dimension of the through bore 40 intothe through-bore. The integral keyway 32 and key portion 42 preclude theloss of otherwise separate locking components which would render theconnection less efficient.

It has been determined that tapers of .6 per foot taper fromapproximately larger cross-dimensions mating along axial lengths of 1 /2give sufficient holding power to secure a typical chair post-chair ironcombination. A key portion raised a minimum of .005" has been foundsufficient to ensure proper positioning of the components together andto prevent rotation of them relative to one another.

While only a single embodiment of the subject invention has beendisclosed, it will be obvious to those skilled in the art that variousother designs are possible. Accordingly, it is desired that theinvention be limited only by the scope of the claims hereinafterfollowing.

What is claimed is:

1. In a chair of the class which includes a base rotatably supporting avertical post having a conically tapered upper free end portionconcentric to its rotational axis, and a post support member fixedagainst axial and rotary movement on said post, said post support memberhaving a similarly tapered conical bore receiving said free end portionof the post, sai-d post being formed with a keyway of uniform widthextending axially from its free upper end toward its medial portion, theinner periphery of said post support member around said bore having anaxially extending eccentric key portion equal in width to and spanningsaid keyway, said key portion pre senting a surface which is displacedradially inwardly with respect to the rest of said inner periphery andis located radially between an imaginary extension of said innerperiphery and a plane common to the opposite edges of said keyway.

2. In combination, a chair post, a chair iron connected to the chairpost, a cross member in the chair iron having an opening aligned withand open to the chair post, an annular post support .member having acylindrical portion fitting within the opening of the cross member witha press fit, said annular post support member having a first shoulderand an intermediate shoulder, said first shoulder and said intermediateshoulder being of cross-dimension greater than the opening in the crossmember, said first shoulder abutting the cross member on its upper sideand the intermediate shoulder abutting the cross member on its lowerside to thereby confine the post support member to the cross member, thepost support member having an elongated bore aligned with and open tothe chair post, said bore being conical throughout its length anddiverging uniformly in the direction toward the chair post to itslargest cross-dimension approximately equal to that of the chair post,thechair post and its end being tapered conically to a similar taperedangle as that of the bore of the post support member and converginguniformly in the direction to- 'ward the chair iron, the tapered end ofthe chair post 5 6 approximately /2 to inch per foot so as to be self-References Cited by the Examiner looking with one another, the chairpost also having an UNITED STATES PATENTS axially-extended keyway in itstapered conical surface 296 017 4/1884 Jordanrecessed toward itslongitudinal center axis, and a raised 2,54zj469 2/1951 Bolens 243*1881out-of-round axially-extended key portion on the tapered 5 2 955 35 1119 Storch 30g 23 conical peripheral surface of the bore of the postsupport CARL W TOMLIN, Primary Examiner. member fitting into the keyWay1n the chair post to therev by prevent relative rotation of the chairpost and post THOMAS E CALLAGHAN Examiner support member. D. W. AROLA,Assistant Examiner.

1. IN A CHAIR OF THE CLASS WHICH INCLUDES A BASE ROTATABLY SUPPORTING A VERTICAL POST HAVING A CONICALLY TAPERED UPPER FREE END PORTION CONCENTRIC TO ITS ROTATIONAL AXIS, AND A POST SUPPORT MEMBER FIXED AGAINST AXIAL AND ROTARY MOVEMENT ON SAID POST, SAID POST SUPPORT MEMBER HAVING A SIMILARLY TAPERED CONICAL BORE RECEIVING SAID FREE END PORTION OF THE POST, SAID POST BEING FORMED WITH A KEYWAY OF UNIFORM WIDTH EXTENDING AXIALLY FROM ITS FREE UPPER END TOWARD ITS MEDIAL PORTION, THE INNER PERIPHERY OF SAID POST SUPPORT MEMBER AROUND SAID BORE HAVING AN AXIALLY EXTENDING ECCENTRIC KEY PORTION EQUAL IN WIDTH TO AND SPANNING SAID KEYWAY, SAID KEY PORTION PRESENTING A SURFACE WHICH IS DISPLACED RADIALLY INWARDLY WITH RESPECT TO THE REST OF SAID INNER PERIPHERY AND IS LOCATED RADIALLY BETWEEEN AN IMAGINARY EXTENSION OF SAID INNER PERIPHERY AND A PLANE COMMON TO THE OPPOSITE EDGES OF SAID KEYWAY. 